Semileptonic and nonleptonic decays of $B_{u,d,s,c}^{\ast }$ in the covariant light-front approach

Abstract

The semileptonic and nonleptonic decays of the b-flavor vector mesons $B_{u,d,s}^{\ast }$ and $B_c^{\ast }$ are investigated within the covariant light-front quark model (CLFQM). By calculating the form factors of the transitions $B_{u,d,s,c}^{\ast }\to P$ under the CLFQM, with $P$ denoting a pseudoscalar meson, i.e., $\pi ,K,{\eta }_c(1S,2S),D_{(s)},B_{(s)}$, we predict and discuss several physical observables, including the branching ratios, polarization fractions $f_L,f_{\Vert }$, and forward-backward asymmetries $A_{FB}$. The total widths of the single-photon radiative decay channels for these b-flavor vector mesons are estimated using their partial widths. In these considered decays, one can find that the semileptonic decays $B_s^{\ast 0}\to D_s^{-}{\ell }^{\prime +}{\nu }_{{\ell }^{\prime }}$ and $B_c^{\ast +}\to B_s^0{\ell }^{\prime +}{\nu }_{{\ell }^{\prime }},{\eta }_c{\ell }^{\prime +}{\nu }_{{\ell }^{\prime }}$, with ${\ell }^{\prime }$ being $e$ or $\tau$, and the nonleptonic channels $B_c^{\ast +}\to B_s^0{\pi }^{+},B_s^0{\rho }^{+}$ have the largest branching ratios, which can reach up to the $10^{-7}$ order, and are most likely to be accessible at the future high-luminosity LHCb and Belle-II experiments.

Comments: 30 pages, 4 figures,accepted for publication in Chin. Phys. C